1/4 inch Copper coated Pipes 1,low carbon steel tube 2,popular size:4.76*0.65mm,4.76*0.7mm, ... refrigerator and other refrigeration equipment. automobile brake system and heaters.2) Standard: ASTM, DIN, GB etc.3) Outside diameter: Φ3.17mm ... : BHG, SPHC, SPCC6) Surface Treatment: Zinc-coated, Copper-coated, etc.7) Inside: N2 pressure inside8) Popular Size: 4.76mmX0.7mm, 6mmX0 ...